Audi is silencing critics of its six-figure R8 sports car by offering a V10 engine for 2009.

The original R8, which launched in 2007, was the company’s first exotic sports car and accomplished its goal of giving low-end Ferraris and top-of-the-line Porsches stiff competition, both in performance and style.

But that wasn’t enough for some enthusiasts.

Even though the 4.2-liter V8 in the current R8 offers outstanding performance, pundits wondered why Audi didn’t adapt the more potent V10 engine from its S8 sedan for use in the hottest car it has ever made.

Today in Detroit, Audi answered the challenge with the introduction of its new R8 5.2. Faster and more powerful than its V8 sibling, this latest exotic from Ingolstadt goes on sale in Europe in the second quarter for 142,400 euros — just over $200,000 at current exchange rates. On-sale dates for other markets, including the United States, are to be determined.

The 5.2-liter V10 in this R8 generates 525 horsepower and 391 lb-ft of torque — considerably more than the V8, which puts out 420 horses and 317 lb-ft of torque. The company did not say how much the R8’s new engine has in common with the V10 in the Audi S8 sedan or the Lamborghini Gallardo (Volkswagen/Audi owns Lamborghini).

Whatever the engine’s lineage, it’s capable of propelling the 3,571-pound R8 to stunning speeds: The car accelerates from zero to 62 mph in 3.9 seconds and has a top speed of 196 mph, according to Audi. The V8-powered R8 is a little slower: Reaching 62 mph in 4.6 seconds and has a top speed of 187 mph.

The V10 gets slightly worse gas mileage than the V8, at an estimated average of 17.17 mpg, versus 17.3 mpg.

Other than the engine, there are few differences between the two R8 models. Audi tweaked the adaptive suspension to cope with the heavier V10 engine, which weighs 69 pounds more than the V8, an Audi spokesman said.

Visually, the models are virtually indistinguishable. The front and rear grilles of the R8 5.2 have fewer bars and different finishes, the side sills are wider, the "side blades" aft of the doors flare out a bit more, and there are two large, oval tailpipes instead of four smaller round ones.

With the new R8 5.2, Audi encroaches further into territory traditionally dominated by Aston Martin, Ferrari and Lamborghini. Now that the company has added the V10, diehard enthusiasts will probably be wondering if Audi is going to put a 12-cylinder engine — perhaps like the one used by corporate cousin Bentley — under the R8’s transparent engine cover.